Selected DOS and BIOS Service Routines

 

BIOS Service 16/00: read keyboard character

 

BIOS Service 1A/02: read real-time clock

 

DOS Service 21/02: display single character to monitor

 

DOS Service 21/05: print character

 

DOS Service 21/09: display character string to monitor

 

DOS Service 21/4C: end program execution and return to DOS

 

DOS Service 27: terminate program but keep program resident in memory (TSR)